This application will test the hypothesis that during parturition glutamine is diverted from fetal hepatic glutamate output to glycogen synthesis. The proposed studies will examine by multiple tracer methodology the interrelationship between fetal hepatic glucose production and glutamine metabolism and glutamate release during spontaneous parturition, and during the stimulation of fetal hepatic gluconeogenesis by cortisol. Other experiments will examine the metabolic and physiologic impact of maintaining a high fetal glutamate supply to the placenta around the time of parturition.